Stationary Stochastic Seismic Response Analysis Of Long-Span Cable-Stayed Bridges Under Non-Uniform Excitation

Not only length, bearing capacity, and headroom of long-span cable-stayed, but also beauty is updated, under enormous development of available design theories, computational analysis, softwares, new materials, and new technologies. It is well-known that bridge is one of lifeline projects, which once damaged under earthquake, will cause traffic paralysis and hindering transportation of emergency succor materials for disaster region, at the same time, it is very difficult to repair in a short time, it seriously affects rescue work, the lives and property are damaged.Compared with general bridges, many complex problems of seismic design about long-span cable-stayed bridge and seismic design need to be studied further deeply. In this thesis, based on theory of non-uniform ground motion and modeling approaches of the stochastic earthquake field, response regularities of long-span cable-stayed bridge subjected to multi-dimensional and multi-support stochastic stationary seismic excitations. The specific contents include the following aspects:(1) It presents the simulation techniques of spatial variability of earthquake, the power spectral density function of seismic acceleration and correlation function with appropriate parameters is proposed for a long-span cable-stayed bridge subjected to tri-directional spatially varying ground motions.(2) Firstly, a comprehensive and systematic stochastic seismic analysis approach is derived, then, seismic responses of long-span cable-stayed bridge under stationary earthquake excitations are studied including one dimensional and multi-dimensional, local site effect, traveling wave effect, coherent effect, respectively. At last, some conclusions are drawn from this research, compared to uniform earthquake excitations, non-uniform earthquake excitations have significantly effect on response of long-span cable-stayed bridge, and spatial varying ground motion is essential to resist seismic of long-span cable-stayed bridge. At the same time, it can be provided an important reference for seismic design of long-span cable-stayed bridge.